Hayat Sumreen, Sabri Anjum N, McHugh Timothy D
Department of Microbiology and Molecular Genetics, University of the Punjab, Quaid-e-Azam Campus.
Department of Microbiology, Government College University.
J Gen Appl Microbiol. 2018 Jan 15;63(6):325-338. doi: 10.2323/jgam.2017.01.004. Epub 2017 Nov 15.
In the form of biofilms, bacteria exhibit more resistance to antibiotics. Biofilm formers can withstand severe conditions and the host's defense system. Therefore, it is necessary to search for effective biofilm inhibitors. In this study, we investigated the effect of a chloroform extract of turmeric on biofilm formation against antibiotic resistant bacteria. The extract exhibited its antibiofilm effect by altering adherence, motility, extracellular polymeric substance (EPS) production and cell surface hydrophobicity; important attributes of biofilm formation. Cell attachment assays indicated that a chloroform extract resulted in a 38.9-60.2% inhibition of cell adherence to a polystyrene surface, and a 44.5-58.3% inhibition to a glass surface. Static biofilm formation assays indicated that a chloroform extract resulted in a 23-74.5% reduction in biofilm formation. The chloroform extract inhibited flagella-directed swarming and swimming motility and pilus-directed twitching motility in a dose-dependent manner. In addition to repression of motility, a chloroform extract also significantly (p < 0.05) altered the hydrophobic behavior, and bacterial strains such as K. pneumoniae and E. cloacae exhibited hydrophilic behavior after the addition of the extract, as compared with control cells. The presence of the extract also significantly (p < 0.05) increased the detachment of biofilms by a surfactant as compared with controls. Fourier transformed infrared spectroscopy (FTIR) had indicated a loss of vital functional groups of polysaccharides and proteins from the EPS of cells treated with a chloroform extract. Gas chromatography mass spectrometry (GC-MS) analysis indicated the presence of many phytochemical constituents, mainly sesquiterpenes and fatty acid groups. These results clearly suggested that turmeric could affect multiple cellular activities in biofilm formers exhibiting antibiotic resistance by modulating adherence, EPS production, motility and surface hydrophobicity.
以生物膜的形式存在时，细菌对抗生素表现出更强的抗性。形成生物膜的细菌能够抵御恶劣环境和宿主的防御系统。因此，有必要寻找有效的生物膜抑制剂。在本研究中，我们调查了姜黄氯仿提取物对耐药菌生物膜形成的影响。该提取物通过改变黏附、运动性、胞外聚合物（EPS）产生和细胞表面疏水性发挥其抗生物膜作用；这些都是生物膜形成的重要特性。细胞黏附试验表明，氯仿提取物对细胞黏附聚苯乙烯表面的抑制率为38.9 - 60.2%，对玻璃表面的抑制率为44.5 - 58.3%。静态生物膜形成试验表明，氯仿提取物使生物膜形成减少了23 - 74.5%。氯仿提取物以剂量依赖的方式抑制鞭毛介导的群游和游动运动性以及菌毛介导的颤动运动性。除了抑制运动性外，氯仿提取物还显著（p < 0.05）改变了细菌的疏水行为，与对照细胞相比，肺炎克雷伯菌和阴沟肠杆菌等菌株在添加提取物后表现出亲水性行为。与对照相比，提取物的存在还显著（p < 0.05）增加了表面活性剂对生物膜的解离作用。傅里叶变换红外光谱（FTIR）表明，用氯仿提取物处理的细胞的EPS中多糖和蛋白质的重要官能团减少。气相色谱 - 质谱联用（GC - MS）分析表明存在许多植物化学成分，主要是倍半萜和脂肪酸基团。这些结果清楚地表明，姜黄可以通过调节黏附、EPS产生、运动性和表面疏水性，影响表现出抗生素抗性的生物膜形成菌的多种细胞活动。
